New genetic technologies combined with a well-characterized genome make the mouse the preferred mammalian model for understanding human diseases and identifying disease genes. Investigators must be able to characterize these models both physiologically and genetically to exploit their full biomedical potential. To realize this potential investigators must make the same basic clinical assessments used in human diagnostic medicine, often including chromosomal and histological analyses. The staff of The Jackson Laboratory (TJL) is at the forefront both in defining the normative biology of standard inbred mice and in characterizing hundreds of new spontaneous and induced mutations of biomedical significance; karyotypic analysis is an essential aspect of this characterization. TJL investigators currently rely on limited part-time cytogenetic services provided by Dr. Davisson's research personnel through her cytogenetic research program. This compromises both the productivity of her program and the research progress in programs requiring karyotypic analysis. Funding is requested for the purchase of a semi-automated spectral karyotyping system, the ASI-SKY System, Applied Spectral Imaging, Inc. Vista CA, that has proven its reliability in human diagnostic medicine and in basic research settings. This system, which also delivers quantitative spectral tissue analysis, represents a cost-efficient mechanism for cytogenetic assessment without requiring cytogenetic expertise, thus extending such analytical capabilities to all interested investigators. The ASI-SKY System will directly enhance the work of 17 TJL investigators with 34 NIH-funded grants who currently lack access to semi-automated, quantitative, digital spectral imaging instrumentation. The ASI-SKY system offers 4 capabilities unavailable at TJL: 1) semi-automated mouse chromosome karyotyping, 2) quantitative measurement of tissue-specific differences in mutant and control mice, 3) simultaneous spectroscopic assessment of multiple distinct proteins in the same tissue sample and 4) capture, analysis and simple colorimetric presentation of emission spectra from every pixel in an image. Delivery of technician-assisted, fee-for-service access to this state-of-the-art instrumentation by the Biological Imaging Service under the guidance of Dr. Davisson, an established cytogeneticist, will greatly enhance ongoing research efforts and assure maximum use of such instrumentation, thus providing a cost-effective way to fill an urgent, and currently unmet need of TJL Research Staff. [unreadable] [unreadable]